Explicit outputs for wasm_cc_binary (#1047)
* Explicit outputs for wasm_cc_binary
* Backwards compatibility
* data_runfiles restore
* restore test_bazel.sh
* Using wrong path on accident
* two separate rules for legacy support
* Added name attribute to wasm_cc_binary rule
diff --git a/bazel/emscripten_toolchain/wasm_binary.py b/bazel/emscripten_toolchain/wasm_binary.py
index 8c67c7c..d7d6142 100644
--- a/bazel/emscripten_toolchain/wasm_binary.py
+++ b/bazel/emscripten_toolchain/wasm_binary.py
@@ -3,16 +3,9 @@
This script will take a tar archive containing the output of the emscripten
toolchain. This file contains any output files produced by a wasm_cc_binary or a
cc_binary built with --config=wasm. The files are extracted into the given
-output path.
+output paths.
-The name of archive is expected to be of the format `foo` or `foo.XXX` and
-the contents are expected to be foo.js and foo.wasm.
-
-Several optional files may also be in the archive, including but not limited to
-foo.js.mem, pthread-main.js, and foo.wasm.map.
-
-If the file is not a tar archive, the passed file will simply be copied to its
-destination.
+The contents of the archive are expected to match the given outputs extnames.
This script and its accompanying Bazel rule should allow you to extract a
WebAssembly binary into a larger web application.
@@ -29,39 +22,34 @@
pass
-def check(f):
- if not os.path.exists(f):
- raise Exception('Expected file in archive: %s' % f)
-
-
def main():
parser = argparse.ArgumentParser()
parser.add_argument('--archive', help='The archive to extract from.')
- parser.add_argument('--output_path', help='The path to extract into.')
+ parser.add_argument('--outputs', help='Comma separated list of files that should be extracted from the archive. Only the extname has to match a file in the archive.')
+ parser.add_argument('--allow_empty_outputs', help='If an output listed in --outputs does not exist, create it anyways.', action='store_true')
args = parser.parse_args()
args.archive = os.path.normpath(args.archive)
+ args.outputs = args.outputs.split(",")
- basename = os.path.basename(args.archive)
- stem = basename.split('.')[0]
-
- # Extract all files from the tarball.
tar = tarfile.open(args.archive)
- tar.extractall(args.output_path)
- # At least one of these two files should exist at this point.
- ensure(os.path.join(args.output_path, stem + '.js'))
- ensure(os.path.join(args.output_path, stem + '.wasm'))
+ for member in tar.getmembers():
+ extname = '.' + member.name.split('.', 1)[1]
+ for idx, output in enumerate(args.outputs):
+ if output.endswith(extname):
+ member_file = tar.extractfile(member)
+ with open(output, "wb") as output_file:
+ output_file.write(member_file.read())
+ args.outputs.pop(idx)
+ break
- # And can optionally contain these extra files.
- ensure(os.path.join(args.output_path, stem + '.wasm.map'))
- ensure(os.path.join(args.output_path, stem + '.worker.js'))
- ensure(os.path.join(args.output_path, stem + '.js.mem'))
- ensure(os.path.join(args.output_path, stem + '.data'))
- ensure(os.path.join(args.output_path, stem + '.fetch.js'))
- ensure(os.path.join(args.output_path, stem + '.js.symbols'))
- ensure(os.path.join(args.output_path, stem + '.wasm.debug.wasm'))
- ensure(os.path.join(args.output_path, stem + '.html'))
+ for output in args.outputs:
+ extname = '.' + output.split('.', 1)[1]
+ if args.allow_empty_outputs:
+ ensure(output)
+ else:
+ print("[ERROR] Archive does not contain file with extname: %s" % extname)
if __name__ == '__main__':
diff --git a/bazel/emscripten_toolchain/wasm_cc_binary.bzl b/bazel/emscripten_toolchain/wasm_cc_binary.bzl
index dbdb238..9cf6328 100644
--- a/bazel/emscripten_toolchain/wasm_cc_binary.bzl
+++ b/bazel/emscripten_toolchain/wasm_cc_binary.bzl
@@ -54,11 +54,81 @@
],
)
-def _wasm_binary_impl(ctx):
- args = ctx.actions.args()
- args.add("--output_path", ctx.outputs.loader.dirname)
- args.add_all("--archive", ctx.files.cc_target)
+_ALLOW_OUTPUT_EXTNAMES = [
+ ".js",
+ ".wasm",
+ ".wasm.map",
+ ".worker.js",
+ ".js.mem",
+ ".data",
+ ".fetch.js",
+ ".js.symbols",
+ ".wasm.debug.wasm",
+ ".html",
+]
+_WASM_BINARY_COMMON_ATTRS = {
+ "backend": attr.string(
+ default = "_default",
+ values = ["_default", "emscripten", "llvm"],
+ ),
+ "cc_target": attr.label(
+ cfg = _wasm_transition,
+ mandatory = True,
+ ),
+ "exit_runtime": attr.bool(
+ default = False,
+ ),
+ "threads": attr.string(
+ default = "_default",
+ values = ["_default", "emscripten", "off"],
+ ),
+ "simd": attr.bool(
+ default = False,
+ ),
+ "_allowlist_function_transition": attr.label(
+ default = "@bazel_tools//tools/allowlists/function_transition_allowlist",
+ ),
+ "_wasm_binary_extractor": attr.label(
+ executable = True,
+ allow_files = True,
+ cfg = "exec",
+ default = Label("@emsdk//emscripten_toolchain:wasm_binary"),
+ ),
+}
+
+def _wasm_cc_binary_impl(ctx):
+ args = ctx.actions.args()
+ cc_target = ctx.attr.cc_target[0]
+
+ for output in ctx.outputs.outputs:
+ valid_extname = False
+ for allowed_extname in _ALLOW_OUTPUT_EXTNAMES:
+ if output.path.endswith(allowed_extname):
+ valid_extname = True
+ break
+ if not valid_extname:
+ fail("Invalid output '{}'. Allowed extnames: {}".format(output.basename, ", ".join(_ALLOW_OUTPUT_EXTNAMES)))
+
+ args.add_all("--archive", ctx.files.cc_target)
+ args.add_joined("--outputs", ctx.outputs.outputs, join_with = ",")
+
+ ctx.actions.run(
+ inputs = ctx.files.cc_target,
+ outputs = ctx.outputs.outputs,
+ arguments = [args],
+ executable = ctx.executable._wasm_binary_extractor,
+ )
+
+ return DefaultInfo(
+ files = depset(ctx.outputs.outputs),
+ # This is needed since rules like web_test usually have a data
+ # dependency on this target.
+ data_runfiles = ctx.runfiles(transitive_files = depset(ctx.outputs.outputs)),
+ )
+
+def _wasm_cc_binary_legacy_impl(ctx):
+ cc_target = ctx.attr.cc_target[0]
outputs = [
ctx.outputs.loader,
ctx.outputs.wasm,
@@ -72,6 +142,11 @@
ctx.outputs.html,
]
+ args = ctx.actions.args()
+ args.add("--allow_empty_outputs")
+ args.add_all("--archive", ctx.files.cc_target)
+ args.add_joined("--outputs", outputs, join_with = ",")
+
ctx.actions.run(
inputs = ctx.files.cc_target,
outputs = outputs,
@@ -87,7 +162,19 @@
data_runfiles = ctx.runfiles(transitive_files = depset(outputs)),
)
-def _wasm_binary_outputs(name, cc_target):
+_wasm_cc_binary = rule(
+ name = "wasm_cc_binary",
+ implementation = _wasm_cc_binary_impl,
+ attrs = dict(
+ _WASM_BINARY_COMMON_ATTRS,
+ outputs = attr.output_list(
+ allow_empty = False,
+ mandatory = True,
+ ),
+ ),
+)
+
+def _wasm_binary_legacy_outputs(name, cc_target):
basename = cc_target.name
basename = basename.split(".")[0]
outputs = {
@@ -105,6 +192,13 @@
return outputs
+_wasm_cc_binary_legacy = rule(
+ name = "wasm_cc_binary",
+ implementation = _wasm_cc_binary_legacy_impl,
+ attrs = _WASM_BINARY_COMMON_ATTRS,
+ outputs = _wasm_binary_legacy_outputs,
+)
+
# Wraps a C++ Blaze target, extracting the appropriate files.
#
# This rule will transition to the emscripten toolchain in order
@@ -113,36 +207,10 @@
# Args:
# name: The name of the rule.
# cc_target: The cc_binary or cc_library to extract files from.
-wasm_cc_binary = rule(
- implementation = _wasm_binary_impl,
- attrs = {
- "backend": attr.string(
- default = "_default",
- values = ["_default", "emscripten", "llvm"],
- ),
- "cc_target": attr.label(
- cfg = _wasm_transition,
- mandatory = True,
- ),
- "exit_runtime": attr.bool(
- default = False,
- ),
- "threads": attr.string(
- default = "_default",
- values = ["_default", "emscripten", "off"],
- ),
- "simd": attr.bool(
- default = False,
- ),
- "_allowlist_function_transition": attr.label(
- default = "@bazel_tools//tools/allowlists/function_transition_allowlist",
- ),
- "_wasm_binary_extractor": attr.label(
- executable = True,
- allow_files = True,
- cfg = "exec",
- default = Label("@emsdk//emscripten_toolchain:wasm_binary"),
- ),
- },
- outputs = _wasm_binary_outputs,
-)
+def wasm_cc_binary(outputs = None, **kwargs):
+ # for backwards compatibility if no outputs are set the deprecated
+ # implementation is used.
+ if not outputs:
+ _wasm_cc_binary_legacy(**kwargs)
+ else:
+ _wasm_cc_binary(outputs = outputs, **kwargs)
diff --git a/bazel/test_external/BUILD b/bazel/test_external/BUILD
index 4e69238..e3a8e9e 100644
--- a/bazel/test_external/BUILD
+++ b/bazel/test_external/BUILD
@@ -8,6 +8,10 @@
wasm_cc_binary(
name = "hello-world-wasm",
cc_target = ":hello-world",
+ outputs = [
+ "hello-world.js",
+ "hello-world.wasm",
+ ],
)
BASE_LINKOPTS = [
